German Published Patent Application No. 197 50 775 describes a method for selecting traffic-information items, which are transmitted by a main station and relate to a route of a vehicle. In this context, the route is determined in the form of route points between a starting point and a target point in the traffic network, and relevant traffic information is selected by defining, in each instance, a zone between two route points and selecting traffic information relating to a location inside the zone to be relevant, while selecting traffic information relating to a location outside the zone as not being relevant. In so doing, the zone is defined as a corridor between two lines, which are parallel to a connecting line between two route points and are at a predetermined or specifiable distance from the connecting line.
German Published Patent Application No. 197 53 170 describes a method for transmitting route information relating to a recommended route of a vehicle in a traffic network, from a main traffic station to a terminal in a vehicle, where the route information relates to route points on the route of the vehicle. In each instance, a route point is defined at a location at which the vehicle can continue in a plurality of directions. The location data determining the location of the route point, the geometric data relating to the intersection geometry of the route point, and the transition data defining the route through the route point are transmitted for each route point.
In addition, a method of transmitting data for assessing a traffic situation is described in German Published Patent Application No. 196 43 454. In the method, data for assessing the traffic situation in route segments of a road network are acquired by a plurality of vehicles working as mobile detectors, and transmitted to a main station. To assess the traffic situation, it is also provided that, in each instance, a current driving profile is formed from the acquired sensor data in the vehicle, and characteristic properties are derived from the current driving profile in the sense of actual values. In addition, characteristic driving-profile properties are formed in the vehicle, in the sense of expected values, using predetermined traffic-situation information. The actual values and the expected values of the driving-profile properties are compared to each other. The result of the comparison is evaluated in the vehicle, using predefined decision criteria, data for assessing the traffic situation only being transmitted to the main station in the cases in which this is provided according to the decision criteria.
Furthermore, German Published Patent Application No. 197 50 774 describes a method for transmitting traffic information relating to a traffic network and representing the traffic situation, from a main traffic station to a terminal of a vehicle, traffic information relating to at least one route of the traffic network being transmitted, in each case, for route segments of the route, at least with predetermined qualification of the traffic situation, in the form of qualified speeds in the speeds representing the route segments.
It is an object of the present invention to provide a method for describing and generating road networks and a road network, in order to ascertain traffic information and/or ascertain driving times, using at least one mobile detector.